Electric ignition device.



and curios.

JOSEPH ARTHUR JEFFERY AND BENJAMIN ALFRED JEFFERY, OF NEWARK, NEW JERSEY.

ELECTRIC IGNITION DEVICE.

intense.

Specification of Letters Patent.

Patented Mar. a, rare.

Application filed September 23, 1908, Serial No. 454,402. Renewed July 19, 1915. Serial No. 40,808.

To all whom it may concern:

Be it known that We, JOSEPH A. JEFFERY and BENJAMIN A. JEFFERY, of Newark, in the county of Essex, State ofv New Jersey, have invented certain new and useful lmprovements in Electric Ignition Devices, of which the following is a specification.

This invention relates to certain new and useful improvements in electric ignition devices, the same being particularly designed as an improvement upon the devices described and claimed in our pending applications for patent filed'August 15th 1906, No. 330,620 and September 27th 1907, No. 394,887, respectively. It will be understood, however, that we do not desire to limit ourselves in this particular.

It is well known that the internal combustion engine must, from the very nature of its ofiice, be started cold, or'at times be worked'on a load where insufficient heat is generated within it to be transmitted to the core of the spark plug, rapidly enough to maintain the latter at a temperature sutiiciently high to volatilize or oxidize any oil that might accumulate on its surface. It is equally well known that a surplus of lubricating oil is used in motors of this class, which oil becomes pulverized or broken into spray by the rapid motion of the piston and is deposited on the insulating block. The latter being cool the oil soon accumulates in the form of drops, or of suflicient thickness to act as an insulator, and as uncarbonized 'oil possesses high insulating qualities, the resistance of the spark gap is greatly increased. This condition'does not exist to any material extent in that class of plugs in which the electrode projects beyond the surface of the insulating block, the capillary attraction being sufli cient to hold even the heavy oilson the electrode to a slight degree, and the electrode having a comparatively large exposed area, the spark will. readily find its escape through the film of oil and jump to the grounded electrode or other pole. In that class of insulators involving the use of an electrode baked in or otherwise embedded in the insulating block it has been found that the escape of the spark, or its passage destruction of both the electrode and the insulating block surrounding it, which soon impairs the operation of the device.

accumulation of uncarbonized oil over the exposed terminal of the electrode, increasing the resistance necessarily raises the potential of the coil or other source of energy, and not only forces the spark to seek an= other path of lesser resistance, but may cause sufficient increase in the potential to break down the insulation of the generating device, or at least cause it to seek a path outside of the cylinder and cause 'a misfire. Again, it has been noted that in those ignition devices in which the sparking terminal comes fiush with the exposed surface of the insulator, when the flush terminal is covered by a drop of oil, the spark will pass through the oilebut will fail to ignite the charge of gas in the cylinder becausethe spark takes place in the oil and not in the gas.

One of theobjects of the present invention is to overcome the foregoing objections and difliculties by providing a path which the spark may take during the time that the oil, or any other accumulation, lies over the exposed end of the electrode, whereby a In the accompanying drawing: Figure 1 is a longitudinal sectional view of an electric ignition device embodying the characteristics of our invention. Fig. 2 is a similar view pf'a slight modification. Figs. 3, 4 and 5 are detail sectional views illustrating additional modifications.

Referring to the drawing, 10 deslgnates an insulating block provided with a central-longitudinal bore 11 having a closed end 12, the opposite end being provided with a head 13. The exposed face of the closed end 12 is provided with a recess 14, and the body of the plug is provided with an annular rib 15. Around the rib 15 is placed a bearing ring 16 and suitable packin 17 is forced between said ring and the bodv of said block. Within the closed end 12 of the block is embedded or otherwise secured a conductor or sparking terminal 18, the inner end of said conductor being in contact with. the reduced end 19 of a conductor 20 located in the bore 11. The open end of the bore is closed by a terminal cap 21 of any preferred construction, said cap being in circuit with the conductor 20. Adjacent the conductor 18 in the closed end of the plug, is embedded or otherwise secured, an auxiliary electrode 22 the outer end of which projects beyond the face of block 10, the inner end of said auxiliary electrodeprojecting into the air space within bore 11 adjacent the reduced end 19 of conductor 20. The bearing ring 16 rests upon an internal shoulder in a supporting bushing 23 in which is supported the ground electrode 24:. The block 10 is secured in position in bushing 23 by means of a second bushing 25 provided with a reduced edge arranged to compress packing 17.

It will be noted that the recess 14 is formed with an approximately fiat face 26 and an outwardly flaring side wall 27. It will also be noted that the outer end of the auxiliary electrode 22 terminates within the edge of said recess. Thus said electrode is protected from injury in the handling of the plug and will not interfere with the terminal 24 when the device is being placed in position. The shape of the recess 14 is such that oil or the like striking the face 26 is conducted away from the exposed end of wire 18 toward the wall 27 by capillary attraction being held by the same force at the annular angular shoulder formed by the junction of said wall and said face until burned oil or otherwise dispelled.

In practice, the current from the source of electrical energy will normally take the path between the fine conductor 18 and the ground wire 24, as this path aflords less resistance than through the path across the air gap to the auxiliary electrode. When, however, some body of high resistance, such as oil, is interposed in the spark gapTthe .spark will jump "the air gap from conductor 20 to the auxiliary electrode 22 and then to the ground'wire 24, thus completing the circuit. ,cJust as soon as the said body of high resistance is burned off or otherwise removed, the resistance of the air gap becomes greater than the resistance through conductor 20 and conductor 18, and the cur rent seeking the path of least resistance will pass through the latter. conductor a. e. the current will follow its normal path.

We have found in practice that excellent results are secured by placing a bodyof material 28 of high resistance around the reduced portion 19 of terminal 20, as illustrated in Fig. 2, and placing the inner end of the auxiliary electrode 22- in contact therewith. This body 28 may be of any suitable material, a disk of carborundum, for instance, although we do not care to limit ourselves in this particular. The same results can be attained by forming the insulating block without the recess and having the auxiliary electrode project laterally from the same as indicated at 29, Fig. 3. ()r the projecting portion of the auxiliary electrode may terminate in a recess 30 as illustrated in F ig. 4, to preventinjury thereto in assembling and other handling. Or, if desired, the conductor 20 and auxiliary electrode 22' may diverge as illustrated in Fig. 5.

From the foregoing it will be noted that we have produced an ignition device in which the insulating block and sparking terminals are relieved of the strains incident to the forcing of the spark through accumulations of oil and the like on and around the electrodes, thereby overcoming the tendency to destroy said block and terminals. It will also be observed that by providing the auxiliary electrode we have produced means forrpositively assuring an ignition of the explosive mixture in the engine, and

at the same time all danger of breaking down the insulation of the generating apparatus, or otherwise injuring the same is reduced to a minimum, thus overcoming all chances of a misfire. It will be further noted that we have produced simple and efficient means for conducting accumulations of oil away from the sparking terminals.

We claim as our invention 1. An electric ignitionl devicecomprising an insulating block provided with a conductor, and means within said block for providing an alternative path for the electric discharge when the circuit through the conductor is impeded.

2. An electric ignition device comprising an insulating block provided with a conductor, and an alternative electrode embedded in said block and arranged to serve as a path for the electric discharge when the normal circuit through the conductor is impeded."

3. An electric ignition device comprising an insulating block provided. with a conductor, an auxiliary electrode embedded in said block and arranged to serve as a path for the electric discharge when the circuit through said conductor is impeded, and means forinterposin a resistance between said conductor and said auxiliary electrode.

4.. An electric ignition device comprising an block provided with a conductor, and an alternative electrode carried by said block and arranged to serve as a path for the electric dischargewhen the circuit through said conductor is impeded,

the inner terminal of said electrode beingseparat'ed from the contiguous portion of said conductor.

5. An electric ingition device comprising an insulating block provided'with a conductor, an alternative electrode embedded in said block and arranged to serve as a path for the electric discharge whenthe circuit through said conductor is impeded, the inner terminal of said electrode being separated from the contiguous portion. of said conductor, and a body of material of high resistance interposed between-said COIldllCr.

tor and said inner terminal.

6. An electric ignition device comprising an insulating block provided with a conductor, an auxiliary electrode carried by said block and arranged to serve as a path for the electric discharge when the circuit through said conductor is impeded, the inner terminal of said electrode being separated from the-contiguous portionof said conductor, and a body of carborundum interposed betweensa'id conductor and said inner terminal.

7. An electric ignition device comprising an insulating block providedwith a longi tudinal bore and closed end, a conductor embedded in said closed end, a second conductor located in said bore and in circuit with the first conductor, and means within said closed end for providing an auxiliary path forthe electric discharge when the circuit through said conductors is impeded.

8. In an electric ignition device, an insulating block providedwith a longitudinal bore and closed end, a conductor embedded in said closed end, a second conductor located in said bore and in circuit with the first conductor, and an auxiliary electrode also embedded in said closed end and arranged to serve as a path for the electricdischarge when the circuit through said conductors is v "impeded.

9. In an electric ignition device, an insulating block provided with a longitudinal bore and closed end, a conductor embedded in said closed end, a second conductor located in said bore and in circuit with the first conductor. an auxiliary electrodeaalso embedded in said closed end and arranged to serve as a patlf-fo'r the electricdischarge when the circuit through said conductors is f' impeded, and meaiis" for interposing a resistance between the inner end of said electrode and thecontiguous' end of the second conductor. i I

10. In an electric ignition device, an in-' sulating block, provided with 'a longitudinal bore and closed end, a conductor embedded in said closed end, a second conductor located in said bore and in circuit with'the first conductor, and an auxiliary electrode also embedded in saidclosed end and arranged to serve as a path for the electric discharge when the circuit through said conductors is impeded, the inner terminal of said electrode being separated from the contiguous portion of the second conductor.

'11. In anelectric ignition device, anmsulating block provided with a longitudinal bore and closed end, a conductor embedded 4 in said closed end, a second conductor located in said bore. and in circuit with the first conductor, 'an auxiliary electrode also embedded in said closed end and arranged to serve as a path for the electric d1scharge when the circuit through said conductors isiimpeded, the inner terminal of said electrode being separated from the contiguous portion of the second conductor, and a body of material of high resistance in terposed between said second conductor and the inner terminal of said electrode.

12. In an electric ignition device," an insulating block provided with a longitudinal bore and closed end, a conductor embedded in said closed end, a. second conductor located in said bore and in circuit with the first conductor, said second conductor being provided with a reduced end, and an auxiliary electrode also embedded in the closedend of said block, the inner end of said electrode terminating adjacent the reduced .endof the second conductor, and arranged to'receive the current from the latter when the circuit through the embedded conductor is impeded. p 13. In an electric ignition device, an msulating block provided with a longitudinal bore andclosed end, a conductor embedded in said closed end,'a second conductor located in said bore and in circuit with. the first conductor, said second conductor being provided with a-reduced end, an' auxiliary electrode also embedded in the closed end cated in said bore and in circuit with the first conductor, and .an auxiliary electrode also embedded in. said closed end and arranged to serve as a path for the electric discharge when the circuit through said conductors is impeded, the outer end of said electrode terminatingwithin said recess.

15. In an electric ignition device, an in sulating block, a conductor having one terminal flush with one end face of said insulating block, and means located within said block for providing an alternative path for -the electric discharge when the circuit through the conductor is impeded.

In testimony whereof, we have signed this specification in the presence of two subscribing witnesses.

JOSEPH ARTHUR JEFFERY.

BENJAMIN ALFRED JEFFERY.

Witnesses:

MORTIMER CLUFF DEWITT, JOSEPH S. SUTPHEN. 

